Manufacture of wall-board and the like



May 10, 1932.

A. E. MILLINGTON MANUFACTURE OF WALL BOARD AND THE LIKE Filed May 26.1927 ll Sheets-Sheet l MANUFACTURE OF WALL BOARD AND THE LIKE Filed May26, 1927 11 shee ts sheet 2 8 vweutoz May 10, 1932. A. E. MILLINGTON1,857,316

MANUFACTURE OF WALL.BOARD AND THE LIKE Filed May 26. 1927 11Sheets-Sheet 3 y 1932- A. E. MILLINGTON 1,857,316

MANUFACTURE OF WALL BOARD AND THE LIKE Filed May 26. 1927 11Sheets-Sheet 4 2 gywm doz 831 /54 Gum/"W y 1932- A. E. MlLLlNGTON1,857,316

MANUFACTURE OF WALL BOARD AND THE LIKE Filed May 26, 1927 Sheets-Sheet 5May 10, 1932. i A E. MlLLlNGTON 1,857,316

7 MANUFACTURE OF WALL BOARD AND THE LIKE Filed May 26, 1927 11Sheets-Sheet 6 May 10, 1932. A. E. MILLINGTON MANUFACTURE OF WALL BOARDAND THE LIKE- Filed May 26. 1927 ll Sheets-Sheet 7 m :5 M 3 n m .I.. #4.FdwhVnnhu M A. E. MILLINGTON MANUFACTURE OF WALL BOARD-AND THE LIKE May10, 1932.

11 Sheets-Sheet 8 Filed May 25. 1927 May 10, 1932. a

A. E; MILLINGTON MANUFACTURE OF WALL BOARD AND THE LIKE 1 927 11Sheets-Sheet 9 Filed May 26 May 10, 1932. A. E. MILLINGTON MANUFACTUREOF WALL BOARD AND THE LIKE Filed May 26, 1927 11 Sheets-Sheet 10 0 FL."I a v u 5 May 10, 1932.

. A. E. MILLINGTON MANUFACTURE OF WALL BOARD AND THE LIKE Filed May 26,1927 11 Sheets-Sheet 1] Patented May 10, 1932 UNITED STATES PATENTOFFICEARTHUR r. mmneron. or semi rmcrsoo, cAuronnn, Assmnoa, BY nmnc'r ANDmnsnn ASSIGNMENTS, 'ro THE UNITED sums nn'rroxmr. mxor 203mm,

OREGON, AS' TRUSTEE r MANUFACTURE OF WALL-BOARD AND THE Applicationfiled May as, 1927. Serial No. 194,288.

This invention relates generally to the manufacture of wall, insulating,and sounddeadening boards and similar materials, and

has particular reference to a new material of the kind mentioned; and tomechanism for producing such material.

A broad object of the invention is to make the waste from sawmill andlumbering operations economically useful, thereby providing a way ofsupplementing the rapidly diminishing available lumber supply.

Another object of the invention is to provide a method of producingfibrous material suitable for use in makin wall boards and the likewhich will yield fi re which is chemically unweakened and which willlend itself to interlacing or mutual entanglement in the board-makingoperations. An incidental ob ject is to provide a method which can becarried on at a very low expense and with a minimum outlay formanufacturing equipment.

Another object of the invention is to provide a Wall board which willhave great strength and a very high degree of insulatingquality. This isaccomplished partly by the peculiar nature and relation of the fibresgiving the strength characteristic and which provides innumerable airgaps or spaces; and partly by' the fact that the non-fibrous'parts ofthe bark from lumbering operationsis included in the board, suchnon-fibrous material possessing to a high degre the desirable insulatingqualities.

Another object is to provide a novel combination of mechanisms, andinterconnections between them, which are ada ted to carry out the novelmethod and r0 uce the novel product at a relatively hig production rateand at a minimum cost.

Other objects and advantages will be apparent from the descriptionhereinafter given and from an examination of the drawings,

which accompany and form a part of this specification.

In said drawings:

Fig. I is a plan view showing in somewhat diagrammatic form the relationof chi ping, screening, and digesting sections of t e apparatus.

vsubsequent operations Fig. 2 is a continuation of Fig. 1, and shows thestock tanks for the cooked materlal and some of the devices subsequentlycalled into action.

Figs. 3 and 4 are views from differentangles of the chi per and some ofthe mechanism associate therewith.

Figs. 5 and 6 are respectively side and end views of the chip screeningapparatus.

Figs. 7 and 8 are respectively a front elevation of the digester and thegearing used for driving the igester.

Figs. 9, 10 and 11 show details of the devices for distributing thecooked material among the storage tanks.

Fig. 12 is a section on-the line 12-42 .of

Fig. 2 and shows among other things the fibre separator machines.

Fig. 13 is a top plan view of the mechanism shown in'Fig. 12.

Figs. 14, 15-, 16, 17 and 18 collectively show the construction of thefibre separating machines.

Figs.- 19 and 20 are complemental sheets showlng the board-formingapparatus as viewed from 19-19 and 2020 of Fig. 2.

Fig. 21 is a plan view of a flow box.

- Stated in a general way, the present invention includes what may betermed a softenlng process of preparing the material for suchpreparationconsisting mainly in cooking sawmill Waste of all kinds, including thenatural percentage of bark, in a week solution of soda ash. Preferably,this cooking operation is carried on in a rotary digester and in thepresence of live steam, although the cooking may be effected in otherways. The term digester is.

used herein as a matter of convenience. As will be apparent later on,the device designated by that name does not, as a matter of fact effectdigestion of its contents within the usual meaning of the term.

In actual practice the rotary digester is filled approximatel to halfofits capacity with wood waste w ich has been reduced to suitable sizes,or under a maximum size, and

the digester then filled with water within 90 per cent, approximately,of its capacity. At any time eforethe cooking operation is started,commercial soda ash may be added to the contents of thedigester in anysuitable way, although all that is necessary is to dump in the properamount of the soda ash for the amount of material in the digester,thereby making unnecessary, chemic'al house's, solution vats, and thelike. The most desirable results are obtained by using about one andone-half pounds of soda ash for each cubic foot of the material to betreated, although the amount of soda ash may be varied for dif-' ferentwoods. The digester is then closed by a manhole cover, and rotation ofthe digester started to tumble the contents. The digester may be run fora short period to cause a thorough commingling of its contents, afterwhich steam may be turned on, or the starting of the digester and theadmission of the steam may be simultaneous.

The rotation of the digester and the ad mission of the steam iscontinued until substantially all of thegums, resins, and the'likeholding the fibres together are separated and largely removed from thefibres. While this is going'on, a bleeder is operating, preferably in anautomatic manner, to remove some of the liquor from the condenser so asto maintain the desired temperature and compensate for or offset theeffects of steam condensation. The preferred amount of soda ash pe cubicfoot of material, that is, one and onehalf'pounds' per cubic foot, willgive a solution in the digester of about 3 Baum. Owing to the steamcondensation and operation of the bleeder'carrying off the. liquor,

the Baum will, however, gradually be lowered until at the end of thecooking operation the Baum will be 1 or possibly less. Even if thenature of the material requires a greater amount of soda ash, the Baumwill seldom exceed 6 with a decrease in the :Baum as the cookingproceeds.

' The operation, as so far described, takes from twelve to twenty-eighthours, according to the volume of the digester contents and a greatdealmore water than is customary in similar processes, the great volumeof water preventing the scorching or charring of the material, which hasin the past been one obstacle in the way of shortening the cooking byincrease of temperature. The

-- steam is preferably admitted near the center of the rotary digester,or on a central line, so that it aids or supplements the rotary movementof the digester in effecting a thorough tumbling and cooking of thecontents of the digester.

When the cooking operation is completed the chips and pieces of barkwills'till have substantially their original sizes and shapes. In otherwords, they are not disintegrated or dissolved by the cooking treatment,this behole is, in the filling position of the digester,-

at the top, and the Water, soda ash, and raw material are dumped orpoured in and the manhole cover bolted in position. The steam isadmitted through a pipe 21 extending through the center of one of thesupporting trunnions for the digester a bleeder 22 ex.- tendingoutwardfrom the trunnion at the opposite side. The admission of steam iscontrolled by the usual valv'e23, and the bleeder is equipped with theusual automatic trap 24:. Associated with the bleeder is a hand operatedvalve 25 and pipe so placed and constructed that it may be operated,when the cooking operation is completed, to relieve the digester fromthe larger part of its internal pressure and much of the liquidcontents.

Diametrically opposite the manhole on the digester is a blow-off pipeand valve 27 which ,is adapted to be connected by a suitable union 28 toa pipe or hose 29 leading to a sewer. The interior of the digesteraround the outlet to the blow-ofi pipe is provided with a perforatedplate or screen 26 of sufiicient fineness to retain in the digestersubstantially all of the useful material while allowing the liquor topass without much interference. This construction is much cheaper andsimpler than the usual blow-pit used in pulpnaking operations, andresults in a corresponding reduction in the cost of plant con- 7struction.

After the liquor has drained off, the remaining contents may be Washedby means of a hose or the like inserted through the manjhole, until allof the liquor and its contents are Washedout, such washing also removingsubstantially all of the remaining dissolved and soluble matter notcarried off with the liquor. This washing operation in the digesterconsumes only a few minutes, and may under certain conditions be omittedin view of a subsequent washing operation later mentioned which iseffected after the material leaves the digester.

After the liquor has been withdrawn and the washing in the digester, ifany, completed, the blow-off. pipe union 28 is disconnected from thedrain and the digester given a half turn to permit the cooked and washedma-' Lemme tacle 31. This receptacle, as shown in Fig.

7, is preferably constructed with its sides converging toward the bottomto concentrate the material toward a screw conveyor 32. This screwconveyor carries the cooked and washed material from the receptacle 31to a chain conveyor 33, Figs. 2, 9 and 10, com rising crossbars. 34 ofthe usual type an inclined as shown in Fig. 10. The. run of-thisconveyor which is used for conveying the material passes above and inclose contact with a screen 35. This screen has small perforations or isof comparatively fine mesh. Located above the screen and cross bars 34is'a set of shower pipes 36 which-thoroughly sprayandwash the materialas it is carried u over the screen 35, the water passing throug thescreen. to. a sewer conduit. .When the washed material finally leavesthe end 37 of the screen it is carried by the conveyor 33 over animperforate surface 39 and above a series of tanks 42, 43 and 44. Theimperforate surface referred to is provided with openings 45, 46, 47,-above the tanks 42, 43, 44, respectively. Each of the openings. isequipped with-a sliding gate. When the conveyor mechanism is running aspreviously described, the ate for the opening 45 is op'en'ab'outone-thir of the way; the gate for the opening 46, two-thirds of the way;and the gate for the opening 47 is full opened so as to clear the entireopening. in this way the material carried by the conveyor is distributedequally among the three tanks, this distribution being maintained untilthe three tanks are filled to the desired extent. The tanks arecollectively of sufficient capacity to receive a number of batches ofcooked and washed material coming from the digester, and when filled inthe way described serve as a means for averaging the results fromthevarious cookings, therebyinsuring a substantial uniformity of thecontents, regardless of slight variations in the cooking process. Aduplicate set of tanks and associated features may be placed at theother side of the conveyor 33.

The tanks 42, 43 and 44 are equipped with rotary agitators 48, drivenby. any suitable connections, as by the gearing and shafts shown, andwhich are connected to a motor, or other suitable source of power. Eachof the tanks 42, 43, 44 is connected to a water supply. Preferably thewater used in the tanks is condensation water from the board drierforming apart of a complete plant, and

the best results are obtained if this water is warm enough to give atemperature of apnext operation, sufiicient water is added to er centreduce the proportion to about 2 material and 98 per cent water, T isadded water is mainly after explained, and a description of forconvenience in pumpthe material to the point mg and conveying e nextoperations are performed.

where th Associated with the three tanks is a'cen-' trifugal stock (pump51, connected to a header 52, the bee er in turn being. connected byvalve-controlled pipes 53 to the different tanks, so that the pump mayconveniently be connected to any tank desired.

'The pump is also connected by a suitable plpe 55 to an elevated flowbox 56, Figs. 12 and 13, containing three compartments 57 58, 59, Fig.21. .The material first enters the compartment 57 and passes through aregulating gate 61 into the compartment 58 and through an outlet 62 tothe upper one of a series of fibre separators described in detail lateron. The compartment 59 is to receive overflow from. compartment 57, overa dam enters a-spread box 66 serving to spread the flow to form a flatsheet conforming in width to the throat or intake opening 67 of a fibrein the drawings employs four of the separators arranged on a descendingincline.

They are all alike, with a single difference herein: one of them,accompanied by an explanation of the difference mentioned, will besufficient.-

The separator 68 resembles in a great many respects the swing hammermachines used for pulverizing ores and clays, and, to a limitedextent,..v certain vegetable growths, such as kelp and sugar cane. Themachines which have been used for pulverizing purposes are, however,unsuitable for the present purpose, and certam' changes have been madeto secure the desired effect upon the material passing through themachine.

The rior machines employed various forms 0 gratings and cutting bars,giving a cuttin and pulverizing actionwhich is highly un esirable in thepresent treatment of the raw stock.

.The machine 68 employed in the present instance comprises a rotor 71,Figs. 14 and 15, consisting of a number of disks supportmg cross bars orrods 72, upon which rods are loosely pivoted iron plates or centrifugalhammers 73. The throat or intake opening 67 of the machine 68 o ens intoa hopper provided with bars 74 w ich are adjustable to cooperate withthe ends of the plates 73 95 separator 68, constituting the first orupperv I when the rotor is turning in the direction of the arrow. Thebestresults, for present purposes, are obtained when the bars 74 are soadjusted. as to leave-an appreciable gap between the ends of the platesand the bars.

' In the prior machines used for the'other purposes above mentioned, theplates 73 usually were constructed from stock {a of an inch thick, butin the present machine these plates are t; twice as many of the lighterand thinner plates are used as were used in the older construction, thelighter and thinner plates being held apart on their pivots by spacersbetween 'them.

In the prior machines the lower part of the enclosure for the rotor wascomposed of a series of sharp-edge cutter bars cooperating with thepivoted plates or hammers 73 to cut the material between the hammersandthe bars. As a result, the previous machines pulverized the material,an effect which is undesirable for present purposes. The presentmachines have a bottom plate 75 with a smooth concave surfacesubstantially concentric to .the axis 7 6 of the rotor 71. The plate 7 5in the separat r is provided with numerous circular perforations, Fig.17, which are preferably of an inch in diameter, although the s ize ofthe perforations may be slightly increased or decreased according to theresult desired.

Considered as a whole, the increased number of lightweight plates orhammers 73, 35

and the smooth interior and perforations-described,- cooperate to brushthe material against the interior of the machine, thereby causing aseparation of the fibres, as distinguished from a cutting or pulverizingacthe hammers finally brushtion upon them, Th

ingthe fibres through the perforations.

second of the separators 78 is the same, in

the machine 68 just de- P every respect, as scribed in detail. Theseparators 81 and 82, however, are different from separator68 in onerespect, as in both separators 81 and 82 the bottom plate 75, instead ofhaving circular perforations, is provided with a series of slots 83(Fig. 18) which are preferably of an inch wide and 1 inch long, theslots extending in a circumferential direction or parallel to thedirection of movement of the plates 73. This slotted constructionresults in retaining all of the material in the interior of theseparator until the fibres have been separated sufiiciently for them tobrush through or escape. through the slots.

By the time the material. has passed through the last separator, thewoody portions will have been reduced to fibres having a hair-likeappearance, many of the .fibres being of considerable length andsubstantially free one from another. Others of the fibres will be onlypartially separated one from another, resulting in what is, in efiect,

of an inch thick, and approximately a coarse fibre. Such coarse fibresare not removed by any screening process, as they are highly desirableinthe present process and product.

For the average wood waste, the four fibre separators operateconsecutively upon the material, and means are provided for directingthe flow from one to the next until the separating operation iscompleted. This directing means is, however, so constructed that byopening a suitable by-pass, one or more of .the machines may be cut out.

In addition to. the by-pass mechanism, means are also provided forregulating the water content of the flow, a change in the water contenteifecting a change in. the results produced in each machine. In otherwords, the progress of the material through any one of the separatorsmay be sped up or retarded by regulating the amount of water, a decreasein the amount of water causing a longer dwell and greater degree offibre sepa ration, and an increase in the supply resulting in a lesserdegree of separation and a coarser condition of the fibre. This by-passand water control'apparatus, and the consequent difference in thecondition of the fibres, as will be clearer later on, combine to afforda means of controlling the density, hardness,- and sound-deadeningqualities of the finalv products. It also gives a flexibility in theoperation of the.separators which makes it possible to adjust orregulate their operation according to the species of the wood in therawmaterial.

When the material has passed through theperforated plate 75 in the fibreseparator 68, it drops upon a slide or trough 91, Fig. 14, whichconducts it to the receiving opening of the separator 8, which openingis like the opening 67 previously described in connection with therefiner 68. The separator 78 is rovided with a similar slide or trough92 leading to the separator 81, and the separator 81 in turn has atrough or slide 93 leading to the final separator 82. Located near thelower end of each of the slidesor troughs 91, 92, 93 is a dam 95 whichmay be lowered to prevent the flow from the preceding separator enteringthe next one. 'When the dam is lowered, a removable plug, not shown, iswithdrawn from an outlet 96, allowing the flow which would otherwisehave passed to the next separator to fall upon a chute or trough 97,which, at its lower end, communicates with a spout 98, inclined asshown, and provided with openings in its bottom above the Below thescreens 91, 92, 93 are imperforate slides or bottoms, provided withoutlets 101, 102, 103, each equipped with a valve 104. Normally thevalves are closed, and after the spaces under the screens have filled upwith water, the further flow is directed into the separators. Wheneverit is desired to remove a part of the water beforethe flow enters thenext separator, the valve in the corresponding outlet 101, 102, or 103,is set to allow all or any desired part of the water content to escapeinto'a trough 105 leading to the return water tank 106. In addition tothe outlets 101, 102, 103, forallowing part of the water to escape, aseparate water supply pipe 107,-Fig. 14, of any suitable construction isprovided with a valve 108 whereby water may be added at the throat ofeach separator, with a consequent speeding of the action in thatparticular machine. Onl one of the pipes 107 is shown in the drawings,but it will be readily understood that each separator has the same watersupply arrangement for the purpose stated.

5. The flow of material leaving the final separator, or the last one inoperation if one or more of the separators has been cut out,

,goes to the trough 98, which has previously been referred to inconnection with the waterao control, and then to whichever one of aseries of stock tanks 111, Figs. 2 and 12, is in condition to receivethe stock. These stock tanks are equipped with rotary agitators 110,each driven by a gear connection 112 and 113 through a shaft 114connected in any desired way with a motor 115. The stock is suspended inthe tanks in a volume of water sufficient to give it about a 2 per centconsistency.

The stock tanks 111 may, if desired, be employed for waterproofing thestock. A suitable waterproofing, material is the ordinary paper-makerssizing, consisting of rosin in semi-liquid or liquid form,the amount ofrosin employed being substantially one-half of one per cent of the dryweight of. the material. This rosin is first introduced into the tanks,and the agitation of the contents of the tanks continued until thefibres are thoroughly coated. An amount of alum about equal to theamountof rosin, is then lntroduced into the tanl s, causing aprecipitation and fixing of the rosin on the fibres.

The tanks 111 are all connected to a header 118 equipped with a separatevalve 119, whereby the tanks may be independently connected to anddisconnected from the header.

The header is connected to a stock pump of 3 suitable construction andcapacity for carrying the stock to the starting end of the boardformingmachine shown in Figs. 2, 19 and 20.

The board-forming machine used is fully described in an applicationfiled by Arthur E. Millington on the 26 day of May, 1927, Serial No.194,289, and needs not, therefore, be described in detail in the presentapplication.

It is suflicient for present 1purposes to say that the board-forming macine com rises a coarse-mesh Fourdrinier wire 121, igs. 19 and 20,inclined upwardly from the breast roll 122 or starting end, withsuitable guides 123 and deckles 124 to permit forming and maintaining apool 125 of considerable depth at the'foot of the incline and extendinga distance often or twelve feet lengthwlse of the wire.

The wire is, as stated in the application referred to, run at-a lowspeed as compared with the usual F ourdrinier wire, the speed preferablybeing approximately from twenty to thirty linear feet per minute. Asalso explained in the application referred to, this results in thefibres tending to move endwise with the flow of water through the meshesof the Fourdrinier wire, thus causing a con-.

siderable percentage of the fibres to be at right angles or other anglestothe face of the finished board. In the finished board the fibres will,therefore, be entangled or interlaced, thereby contributing in a markeddegree to making the finished board wholly selfsustaining, that is,capable of resisting break ing and other strains without the use ofbinders or fillers of any kind to cause mutual adhesion of the fibres.

The apparatus and process as so far described can be used in producingthe fibrous stock and the finished board from any of the softer woods.It is, however, preferable to for use what may be termed the long-fibrewoods,

particularly satisfactory results having been obtained from the wastederived from sugar and white ines, and from fir. Fir is particularlysuitable for the purpose, and a percentage of fir included in the wastefrom other woods increases the desirable qualities of the finishedproduct.

Asstated at the outset, the raw material includes the natural percentageof bark. Bark contains some fibrous material and a large percentage ofnon-fibrous material. 1 The non-fibrous material is particularlyvaluable .in wall-board and similar, products because of its highinsulating qualities, approaching cork in that respect. The apparatusand method as .a whole is adapted to retain the larger part of thenon-fibrous art of the bark in the stock, and after the re ningoperation the fibrous part of the stock engages or enmeshes thenon-fibrous pieces. This relation of the fibres and non-fibrous materialis thereafter maintained and is found in the finished board.

It will be noted that the apparatus as so far described makes noprovislon for screening out coarser fibres, provided that the fibres areunder a useful maximum. In actual practice the stock comprises fibres ofwidely varying sizes and lengths, the long fibres giving the resistanceto breaking strains and the shorter fibres serving as binders to tie thelonger fibres together. The short fibres incidentally insure the properenmeshment of the nonfibrous portions of the bark. These various sizesand lengths of the fibres and the portions of the bark all contribute tothe production of a board which contains the air voids and cells whichhave been found so desirable in insulating and sound-deadening mater al.

The waste from the sawmill and lumbering operations, including slabs,edgmgs, limbs, and the like, may be reduced to pieces of a suitable sizefor the subsequent operatlons in any suitable way. Preferably, however,a conveyor system, designated generally as 131, Figs. 1, 3 and 4,conveys the waste abov e the hopper 132 of a. chipper 133. ThIS chipperis preferably of the disk type, with kmves 134 which are adjustable toregulate the s1ze o f the chips. The process asa Whole 1s facilitated bykeeping all of the waste under a maximum thickness 0f.one inch and alength of approximately two inches. The length 1s not of importance, butthe maxnnum length indicated is preferred, because it has been found tobe the best one for satisfactory cooking and fiberizing.

After passing through the chipper the chips fall intoa bin 140,preferably havmg sides and bottoms directing thechips to a belt-conveyor141. The conveyor is inclined upward to elevate the chips to a hopper orchute 142 leading into the interior of a rotary chip screen 144, Figs. 1and 5. Th1s screen consists of two tubular screens 145 and 146, onewithin the other, the inner screen being of any predetermined mesh whichwill screen out from the chipped waste any part of the material which istoo coarse or too long for efiicient use. The outer screen 145 is of afiner mesh than the inner screen and is intended principally to screenout dust and particles which are toosmall to serve a useful purpose inthe final product.

The screen, as shown, is on an inclined axle, and when the screenedmaterial eventually reaches the lower end the rejects leave the whichruns to a chip-bin above the digester hcreinbefore described, from whichbin the chipped material is removed for use in charging the digester.

In describing the various features of the mechanism and the varioussteps involved in the process, it has been necessary to state operationusual at this point may be omitted.

While the description' ha s gone into great detail with respect to thevarious features and ideas, it is not the invention to be limited tosuch details except as they may be included in the following claims.

Vhat is claimed is 1. The process of making wall board from saw millwaste and the like which includes the steps of reducing the waste topieces which will pass through a screen of a predetermined mesh, boilingthe reduced waste in a weak solution of soda ash long enough to separatethe gums and resins from the fibers and loosen the fibers to soften thewaste, washing the material to remove the gums and resins from thefibers, and then mechanically effectingseparation of the fibers wherebyto provide a finished board of soft, self-sustaining material capable ofresisting breaking and other strains without use of a binder or filler.

2. The process of making wall board from saw mill waste and the likewhich includes the steps of reducing the larger pieces of waste topieces which will pass through a screen] of a pretermined mesh,agitating the waste in a weak solution of soda ash in the presence oflive steam long enough to separate the gums and resins from the fibersin the waste, said solution not being in excess of two pounds of sodaash for each cubic foot of the material to be treated, washing thematerial to remove the separated gums and resins from the fibers andthen subjecting the washed material to frictional action whereby toeffect separation of the fibers in the material whereby to provide afinished board of soft self-sustaining material capable of resistingbreaking and other strains without use of a hinder or filler.

3. The herein described process of making wall board which comprisesrunning saw mill waste including bark through a chipper, screening outall material over certain dimensions and subjecting the remainder tosteam under pressure and a solution of soda ash to soften the material,said solution not being in excess of two pounds of soda ash for eachcubic foot of the material to be treated, and then subjecting thematerial to frictional impacts to effect separation of the fiberstherein, then suspending the material in a large volume of'water andagitating same to cause further separation of the fibers and athoroughcommingling of the fibrous and non-fibrous portions of thematerial, and then employing said water as a vehicle for carrying thesuspended material to the starting on d of a board making apparatus. v

4; A process of making wall board which comprises reducing the wastefroma lumbering operation to pieces under a predetermined maximum thicknessand length, tumbling such reduced material in the presence of live steamand a solution of soda ash to effect softcnin of all of the material anda partial liberation of the fibers in the woody portions of the materialwhile maintaining vide a finished board of soft self-sustaining materialcapable of resisting breaking and other strains without use of a binderor filler.

5. The herein described process of making wall board which comprisesreducing saw mill waste, including bark, to pieces which are all under apredetermined thickness and length, tumbling said reduced waste in thepresence of live steam'under pressure and a solution of soda ash underBaum 5 to effect softening of the fibers in the waste and to dissolvethe gums and resins binding the fibers together, washing the material toremove dissolved and water soluble matter from the material, subjectingthe washed material to a brushing action to effect separation of thefibers, agitating the separated fibers in a large volume of waterto'efi'ect commingling of the fibers, suspending the fibers ina waterproofing solution, and conducting said solution and suspended materialto the starting end of a board making 'apparatus whereby to provide afinished board of soft self-sustaining material capable of resistingbreaking other strains without use of a binder or filler.

6. A process of making insulating wall board which comprises reducingthe waste, including bark, from a'lumbering operation to pieces under apredetermined maximum thickness and length, subjecting such reducedmaterial to agitation in the presence of steam pressure and a weaksolution of soda ash to efi'ect softening of all of the material and apartial liberation of the fibers of the woody pieces of the material,said solution not being in excess of two pounds of soda ash for eachcubic foot of the material to be treated, washing such softened materialin such a way as to remove the soda ash and any dissolved and watersoluble matter while retaining the solids and fibrous material,mechanically separating the fibers .in the woody pieces of the washedmaterial, agitating the fibrous and non-fibrous material in water toeffect commingling of said materials, and then forming the commingledmaterial into boards'and board of soft selfrsustaining material cadryingsame whereby to provide a finished pable' of resisting breaking otherstrains without use of binders or fillers.

7. A process of making wall board which comprises reducing the waste,including bark, from a lumbering operation to pieces under apredetermined maximum size, subjecting said reduced material toagitation in the presence of steam and a weak solution of soda ash ofsufiicient volume to protect the material from charring and effectsoftening of all of the material, said solution not being in excess oftwo pounds of soda ash for each ,cubic foot of the material to betreated, washing such softened material in such a way as to removedissolved, detached and soluble matter while retaining the solids andfibrous material, subjecting the washed material to the successiveaction of fiber separators arranged in series to effect separation ofthe fibers in the woody part of the waste, suspending the separatedfibers 'in alter and removing the water as an incident to forming thefibers into boards.

8. A process of making wall board which comprises reducing the waste,including the bark, from a lumbering and sawmill operation to piecesunder a predetermined maximum size, subjecting such reduced material toagitation in the resence of and by steam and a solution of sot a ash ofless than Baum 6 total to soften the material and-remove the resins andgums therefrom without substantial disintegration of the material,removing the solution and resins and gums contained therein, washing thematerial to remove any remaining soda ash, gums and resins whileretaining the solids and fibrous material, mechanically separating thefibers in the woody parts of the washed material, then alining andinterlacing the fibrous material and enmeshing the solids and formingsame intov a sheet and then pressing and drying same whereby to providea finished board of soft self-sustaining material capable ofresignature.

ARTHUR E. MILLINGTON.

